Abstract

Multiple-token-based media access control (MAC) protocols are investigated for an efficient optical-burst-switching (OBS) ring network with nodes using a tunable transmitter, tunable receiver (TT-TR), since it suffers from resource contention due to the limited network resources. As tokens manipulate the wavelength accessibility and destination queues decide the burst scheduling, token-releasing discipline (TRD) and queue-scheduling discipline (QSD) are crucial. Two TRD schemes that were proposed to avoid source and wavelength contention are reviewed. Three QSD schemes differing in how to group round-robin queues are proposed to avoid or reduce the receiver contention. The performance for different TRD and QSD protocols are simulated and evaluated.